Recyclable ruthenium catalysts for metathesis reactions

ABSTRACT

The invention relates to novel carbene ligands and their incorporated monomeric and resin/polymer linked ruthenium catalysts, which are recyclable and highly active for olefin metathesis reactions. It is disclosed that significant electronic effect of different substituted 2-alkoxybenzylidene ligands on the catalytic activity and stability of corresponding carbene ruthenium complexes, some of novel ruthenium complexes in the invention can be broadly used as catalysts highly efficient for olefin metathesis reactions, particularly in ring-closing (RCM), ring-opening (ROM), ring-opening metathesis polymerization (ROMP) and cross metathesis (CM) in high yield. The invention also relates to preparation of new ruthenium complexes and the use in metathesis.

This application is a Continuation of U.S. application Ser. No.12/604,818, filed on Oct. 23, 2009, now allowed, which is a Continuationof U.S. application Ser. No. 11/478,610, filed on Jul. 3, 2006, now U.S.Pat. No. 7,632,772.

FIELD OF THE INVENTION

The present invention relates to novel ligands and their incorporatedmonomeric and resin/polymer linked ruthenium catalysts, which arerecyclable and highly active for olefin metathesis reactions. Theinvention also relates to preparation of new ruthenium complexes and theuse thereof in metathesis.

BACKGROUND OF THE INVENTION

The metathesis mechanism was proposed by 2005 Nobel laureates YvesChauvin in the early 1970's. The metathesis reactions were practicallycarried out with transition metal catalysts in the 1990's by two other2005 Nobel laureates, Robert H. Grubbs and Richard R. Schrock. Olefinmetathesis catalyzed by transition metal carbene complexes is broadlyemployed in organic synthesis, particularly in drug discovery anddevelopment of polymeric materials and industrial syntheses. Since the1990's, the metathesis reactions have been intensively studied andseveral kinds of valuable transition metal complexes have been reportedas active metathesis catalysts, for examples, Grubbs et al., J. Am.Chem. Soc. 1992, 114, 3974-3975, Org. Lett. 1999, 1, 953-956, WO 9604289A1, WO 2000071554 A2, reported the first and second generation of Rucatalysts with good metathesis activity, but the Ru catalysts withtricyclohexylphosphine ligand is unstable in air and water, and thecatalytic activity is not good enough for some multiple substitutedolefin substrates. Hoveyda et al., J. Am. Chem. Soc. 1999, 121, 791-799,J. Am. Chem. Soc. 2000, 122, 8168-8179, US 20020107138 A1 and U.S. Pat.No. 6,921,735 B2, developed ruthenium complexes with new monomeric anddendritic alkoxybenzylidene ligand based Ru catalysts, whichalkoxybenzylidene ligand based Ru catalysts offer higher activity andbetter stability in comparison to Grubbs Ru catalysts withoutalkoxybenzylidene ligands. Grela et al., Angew. Chem. Int. Ed. 2002, 41,4038-4039, WO 04035596 A1, and Blechert et al., US20030220512 A1,improved the catalytic activity by incorporating some substitutedalkoxybenzylidene ligands instead of Hoveyda's non-substitutedalkoxybenzylidene ligands in metathesis reactions. However, adisadvantage of all reported Ru catalysts are obviouslysubstrate-dependent for different kinds of reported ruthenium complexesin metathesis reactions with multiple functionally substitutedsubstrates.

Currently, metathesis reactions have been becoming crucial steps inchemical and pharmaceutical industries. To overcome the activity andsubstrate-dependent problem, it is a goal to develop more active andrecyclable catalysts as an alternative to some well-known catalysts formetathesis reactions, which could avoid the metal contamination ofmetathesis products and reduce the cost of ruthenium catalysts when theRu catalysts are used in manufacturing.

SUMMARY OF THE INVENTION

The present invention involves novel carbene ligands and their monomericand resin, PEG, polymer linked ruthenium complexes that can be used ashighly active metathesis catalysts in RCM, CM, and ROMP. The metathesiscatalysts are ruthenium complexes with different functionallysubstituted ‘alkoxybenzylidene’ carbene ligand, and the resin/polymerlinked ruthenium complexes are chemically bounded on the surface of theresins, PEGs, and polymers that permit the reuse and recovery of thecatalysts from the reaction mixture. The new ruthenium complexes of theinvention can be in monomeric and polymeric forms that catalyzedifferent kinds of metathesis reactions in a very efficient manner. Theresin- and PEG-linked metathesis catalysts of the invention offer greatadvantage in recyclable utility, and leave little or no trace of toxicmetal contamination within the product of olefin metathesis reactions.The catalysts have broad application in the chemical and pharmaceuticalindustries.

Thus, the present invention comprises novel Ru complexes of thefollowing formula I, which has been evaluated to be highly active andefficient for metathesis reactions with multi-substituted olefinsubstrates and can be broadly used as an alternative to the existingcatalysts.

In one aspect, the present invention provides a transition catalysthaving the following structure I:

wherein:

X¹ and X² are the same or different and each selected fromelectron-withdrawing anionic ligands, and both X¹ and X² could be linkedeach other via the carbon-carbon and/or carbon-heteroatom bonds;

Y is a neutral two-electron donor selected from oxygen, sulfur, nitrogenor phosphorus;

R is H, halogen atom, alkyl, alkoxy, aryl, aryloxy, alkylcarbonyl,arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl(RCO₂—), cyano, nitro, amido, amino, aminosulfonyl,N-heteroarylsulfonyl, alkylsulfonyl, arylsulfonyl, alkylsulfinyl,arylsulfinyl, alkylthio, arylthio, or sulfonamido group;

R¹ and R² are each H, Br, I, alkyl, alkoxy, aryl, aryloxy,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, carboxyl,amido, amino, heteroaryl, alkylthio, arylthio, or sulfonamido group;

R³ is an alkyl, aryl, heteroaryl, alkylcarbonyl, arylcarbonyl,thiocarbonyl, or aminocarbonyl group;

EWG is an electron withdrawing group and selected from aminosulfonyl,amidosulfonyl, N-heteroarylsulfonyl, arylsulfonyl, arylsulfinyl,arylcarbonyl, alkylcarbonyl, aryloxycarbonyl, aminocarbonyl, amido,sulfonamido, chloro, fluoro, proton, or haloalkyl group; and

L is an electron donating ligand, which could be linked with X¹ via thecarbon-carbon and/or carbon-heteroatom bonds.

In preferred embodiment, X¹ and X² each is chloride (Cl), Y is oxygen(O), R is H, Cl, F, or C₁₋₈ alkoxycarbonyl group, R¹ and R² each is H,R³ is a lower alkyl or aryl group, EWG is selected from C₁₋₁₂N-alkylaminosulfonyl, C₄₋₁₂ N-heteroarylsulfonyl, C₄₋₁₂ aminocarbonyl,C₆₋₁₂ arylsulfonyl, C₁₋₁₂ alkylcarbonyl, C₆₋₁₂ arylcarbonyl, C₆₋₁₂aryloxycarbonyl, Cl, F, or trifluoromethyl group, L is PCy₃ or H₂IMes.

In another aspect, the present invention also provides a compositioncomprising a transition catalyst having the following resin, PEG, andpolymer linked structure IIIa-IIId (sometimes collectively referred toas “III”):

wherein:

G is a kind of support materials selected from resins, polymers, PEGs,or silica gel having amino, hydroxy, alkylthio, haloalkyl, or carboxylicgroup on the surface or terminal;

X¹, X², Y, R¹, R², R³, L, EWG each is as defined in the structure I,respectively.

In preferred embodiment, G is resins, PEGs, or polymers having the aminoor hydroxy group on the surface, X¹ and X² each is chloride (Cl), Y isoxygen (O), R is H, Cl, F, or C₁₋₈ alkoxycarbonyl group, R¹ and R² eachis H, R³ is a lower alkyl or aryl group, EWG is selected from C₁₋₁₂N-alkylaminosulfonyl, C₄₋₁₂ N-heteroarylsulfonyl, C₄₋₁₂ aminocarbonyl,C₆₋₁₂ arylsulfonyl, C₁₋₁₂ alkylcarbonyl, C₆₋₁₂ arylcarbonyl, C₆₋₁₂aryloxycarbonyl, Cl, F, or trifluoromethyl group, L is H₂IMes or PCy₃.

Details of the invention are set forth in the description of the newligand synthesis and complex preparation below. The objects andadvantages of the invention will be apparent from the description.

DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises two novel classes of carbene ligands andruthenium complexes as catalysts more active than prior reportedmetathesis catalysts and more efficient for olefin metathesis reactions.Moreover, the resin and polymer linked ruthenium complexes (formulaIII), prepared by loading the new ligands on surface of the resins andpolymers via the coupling and/or substitution reactions, can be easilyrecovered and reused by simple filtration from the reaction mixture oncethe reaction is completed.

The metathesis catalysts of the present invention comprise novelmonomeric ruthenium complexes having the structure of Formula I, andtheir corresponding resin and polymer linked catalysts having thestructure of Formula III. The novel monomeric and resin/polymer-linkedrecyclable catalysts (1.0-5.0 mol %) can catalyze a variety of olefinmetathesis reactions in high yield in DCM, DCE or toluene. The monomericruthenium catalysts can be recovered by precipitation in MeOH or othersolvents, and the resin and polymer linked catalysts can be recoveredeasily from the reaction mixture by simple filtration.

Synthesis of the new alkoxybenzylidene ligands and ruthenium complexes:for new carbene ligands and monomeric ruthenium complexes having thestructure of Formula 2 can be prepared based on four of alternativeprocedures in the following Schemes 1-4, respectively. In Scheme 1, itwas reported by M. Yamaguchi et al (J. Org. Chem. 1998, 63, 7298-7305)to carry out ortho-vinylation reaction regioselectively with ethyne anddifferent substituted phenols to offer diversity of substituted2-alkoxystyrene ligands (V).

Based on four alternative synthetic procedures in Schemes 1-4, there aredifferent kinds of substituted 2-alkoxystyrene ligands (V) and Rucomplexes (2) prepared. Moreover, significant substituent effect ofdifferent substituted 2-alkoxybenzylidene ligands on the stability andactivity of Ru complexes has been observed, and some novel Ru catalystshave been developed much more active than prior reported Ru catalystsfor different kinds of metathesis reactions.

Significant Electronic effect of substituted 2-alkoxybenzylidene ligandson the stability of Ru complexes: To study the effect of substituted2-alkoxybenzylidene ligands on the stability and activity of Rucomplexes, different kinds of 3-substituted 2-alkoxybenzylidene ligands(4a-i) were prepared based on the procedure shown in Scheme 1.Surprisingly, during preparation of Ru complex with 3-R¹ substituted2-isopropylbenzylidene ligand, when R¹ is an electron withdrawing group,it was failed to obtain some desired Ru complexes 5a-i via the followingreported procedure in Scheme 5 (Hoveyda et al, J. Am. Chem. Soc. 1999,121, 791-799, US20020107138).

It appears that 3-electron-withdrawing group substituted2-isopropylbenzylidene ligands 4a-i result in the unexpecteddecomposition during preparation of Ru complexes 5a-i, which means thatthe electronic effect of 3-electron-withdrawing substituents on thestability of 5a-i is significant. Based on the significant electroniceffect on the stability and catalytic activity of Ru complexes, it ispossible to develop more active Ru catalysts by evaluating theelectronic effect of different substituted 2-akloxybenzylidene ligandson the stability and activity of Ru catalysts 7a-n as shown in Scheme 6.Based on synthetic Schemes 1-3, complexes 6a-n in Scheme 6 have beenprepared in good yield, and the catalytic activity has been studied forseveral metathesis reactions with different multi-substituted olefinsubstrates 11 & 13.

All of 13 Ru complexes 7a-n have been evaluated for activity study bycatalyzing the RCM reaction with substrate 11 in Equation 1, and thekinetic result for each catalyst is listed in Table 1. It was found thatthe novel catalyst 7k has the best activity of 13 studied complexes 7a-nwith 5-EWG substituted 2-isopropoxybenzylidene ligands. Moreover, the Rucomplexes with both 4-R and 5-EWG substituted ligands (e.g., 6b with4,5-dichloro and 6b with difluoro substituted ligands) have bettercatalytic activity than the complexes with single 5-EWG substitutedligand, e.g., 6a and 6c, respectively. Based on the structure ofcatalyst 7k, it is more interested to develop more active Ru catalystsby preparing new Ru complexes (9a-j, Scheme 8) with diversity of novel5-aminosulfonyl substituted 2-alkoxystyrene ligands 8a-j (Scheme 7) foractivity study.

To study the relative catalytic activity, two olefin substrates 11 an 13in Equations 1 and 2 were selected for RCM reactions with differentcatalysts 7a-n, and 9a-j, respectively. Other five prior known Rucatalysts 10a-e in Scheme 9 (Hoveyda et al, J. Am. Chem. Soc. 1999, 121,791-799, US20020107138, Grubbs et al. J. Am. Chem. Soc. 1992, 114,3974-3975, Org. Lett. 1999, 1, 953-956, WO 9604289 A1, WO 2000071554 A2,Grela et al, Angew. Chem. Int. Ed. 2002, 41, 4038-4039, WO 04035596 A1)are also selected for the metathesis activity study of substrates 11 and13 in comparison to all new Ru catalysts in the present invention.Because of the EWG and steric effect of both 1,5-dichloro and3′,3′-dimethyl-vinyl substituents on the metathesis reactions, theunique olefin substrate 13 is much more difficult than another commonsubstrate 11 for Ru catalysts to catalyze the RCM reaction, so compound13 is a better olefin substrate to be used for evaluation of more activemetathesis catalysts. The experimental results of catalytic activity fordifferent catalysts 7a-n, 9a-j and 10a-e are listed in Tables 1 & 2,respectively. Furthermore, when the phenyl is replaced with methyl atvinyl group of substrate 11, the RCM under the same catalyst conditionis completed in shorter time, which means that the alkyl substitutedolefin substrates are easier to carry out RCM reactions than the arylsubstituted olefin substrates under the reaction condition in Equation1.

TABLE 1 Activity Study of Ru Complexes for Substrate 11 Conversion (% byHPLC) Entry Catalyst 10 min 30 min 1.5 hr 3.0 hr  1  7a 85 96 100  2  7b88 100  3  7c 81 87 94 >97  4  7d 83 91 >97  5  7e 51 82 92 100  6  7f83 94 100  7  7g 84 >97  8  7h 87 98  9  7i 88 >97 10  7j 90 98 11  7k91 100 12  7m 89 94 >98 13  7n 80 91 94 >97 14  9g 66 84 92 >98 15  9h90 95 100 16  9j 82 91 97 100 17 10b 71 88 95 >97 18 10d 12 23 37 81

TABLE 2 Metathesis Activity of Different Ru Complexes for Substrate 13Conversion (% by HPLC) Entry Catalyst 10 min 30 min 1.5 hr 3.0 hrOvernight 1  7a 26 51 76 86 100 2  7f 28 54 89 >98 3  7i 23 47 75 88 >964  7k 76 92 100 5  9a 45 59 89 100 6  9b 85 >98 7  9c 55 81 94 100 8  9d31 49 67 84 100 9  9e 48 82 94 100 10  9f 20 43 71 86 >97 11  9g 32 5978 89 100 12  9h 28 61 86 92 100 13  9i 60 81 94 >98 14  9j 32 60 7986 >97 15 19a 2 5 23 46 100 16 19b 7 28 61 75 100 17 10b 9 18 32 63 >9518 10d 3 7 16 52 92 19 10e 49 77 89 100

Based on the kinetic results, it is determined that some novel Rucatalysts (7k, 9a-9c, and 9i) with 5-dimethylaminosulfonyl and5-(N-heteroarylsulfonyl) substituted 2-isopropoxybenzylidene ligand arevery active catalysts and much more active than other evaluated Rucatalysts prior known catalysts 10a-e in Tables 1 & 2. Some of newcatalysts 7a-n and 9a-j with 5-EWG (e.g., EWG=Cl, F, COAr, CONH₂, SO₂Ar,etc.) are also air-stable and highly active for different kinds ofmetathesis reactions. Based on the activity study in the presentinvention, the catalyst 9b is the most active catalysts of all surveyedRu complexes, but it is not as stable as other catalysts with single5-amino-sulfonyl substituted 2-alkoxybenzylidene ligands, e.g., 7a, 7k,9a, 9c and 9i. Based on the valuable results in Schemes 6, 7, 8 andTables 1 & 2, several novel active Ru catalysts (e.g., 7a, 7b, 7c, 7f,7j, 7k, 9a, 9c and 9i) can be broadly used in different kinds ofmetathesis reactions as an alternative to prior existing catalysts, andsome novel catalysts with 5-aminosulfonyl-2-alkoxybenzylidene ligands(e.g., 7a, 7k, 9a, 9c and 9i) are more reactive and preferred formulti-substituted olefin substrates.

Resin/Polymer Supported Recyclable Ru Catalysts: To develop somerecyclable and reusable Ru catalysts, two new Ru catalysts 9f and 9gwith an ester group in Scheme 8 can be chemically bounded on the surfaceof support materials, e.g., resins, polymers, PEGs, and silica gel bythe following new developed process for scale-up production in Scheme10.

The resin and PEG linked Ru catalysts 19a and 19b have been evaluatedfor the relative activity for different metathesis reactions inEquations 3 & 4.

Resin linked Ru catalysts 18a and 19a are easily recovered by filtrationand reusable for metathesis reactions effectively for 3-5 times, andboth catalysts 18a and 19a also work well for less hindered olefinsubstrates 20 and 22. However, the resin linked Ru catalysts 18a and 19ado not work actively for substrate 13 because of the steric effect ofdimethyl substituted vinyl group.

Cross metathesis (CM) has been also studied with styrene substrate 24and Ru catalysts 9a and 9d in Equation 5. The CM product isregio-selective transisomer product 25 (>95% by ¹HNMR).

Two Alternative Production Procedures for Preparation of Some HighlyActive Metathesis Catalysts with 5-EWG Substituted 2-AlkoxybenzylideneLigands: As described in Scheme 4, based on some references and newprocess development, there are following two alternative proceduresdeveloped for scale-up production of different 5-EWG substituted2-alkoxybenzylidene ligands. When EWG is Cl, F and H, it is no problemto prepare Ru complexes 7a and 7d directly by replacing ligand P(Ph)₃ ofintermediate 28 with another ligand H₂IMes in Scheme 11. Each reactionproduct in Schemes 11 & 13 could be confirmed by determining thechemical shift change of ¹HNMR, ³¹P-NMR, and/or ¹⁹F-NMR. The typicalchemical shift changes of the isopropoxy and vinyl protons for eachreaction product shown in Scheme 11 are listed in Scheme 12.

However, the ligand P(Ph)₃ can not be directly replaced with ligandH₂IMes when EWG is SO₂NR₂ and NO₂. To prepare Ru complexes 7k and 10ewhen EWG is 5-SO₂NMe₂ and NO₂, respectively, it is required to replacethe P(Ph)₃ of intermediate 33 with PCy₃ first, followed by substitutingPCy₃ of intermediate 34 with H₂IMes to have the desired Ru complexes 7kand 10e prepared in good yield in Scheme 13. The typical chemical shiftchanges of the isopropoxy and vinyl/alkoxybenzylidene protons for eachreaction product shown in Scheme 13 are listed in Scheme 14.

When ligand L is PCy₃ instead of H₂IMes such as the Ru complexes 29a and34a, the complex 34a is also very active for some metathesis reactionswith less substituted olefin substrates, e.g, compounds 36 and 38, butthe activity and stability are not as good as the complex 7k and 9j withH₂IMes. Three new Ru complexes with different SO₂NR₂ and R³ have beenprepared in Scheme 15 and their activity has been studied in Equation 6,and metathesis results are listed in Tables 3 & 4.

TABLE 3 Activity Study of New Ru Complexes for Subsrtate 36 Conversion(% by HPLC) Entry Catalyst 10 min 30 min 1.5 hr 3.0 hr 1 34a 71  82  8691 2 35a 73  92 100 3 35b 95 100

TABLE 4 Activity Study of New Ru Complexes for Subsrtate 38 Conversion(% by HPLC) Entry Catalyst 10 min 30 min 1.5 hr 3.0 hr 1 34a  5 28 71 862 35b 24 63 89 99

It suggests in Tables 3 & 4 that the new Ru catalyst 45b with PCy₃ligand is more active than catalysts 34a and 35a.

Based on all observed results, it is founded that the Ru complexes withdialkylaminosulfonyl and N-heteroarylsulfonyl ligands such as 7k, 9a and9b are a series of the most active metathesis catalysts in comparisonwith diversity of other different substituted 2-alkoxybenzylideneligands, e.g., catalysts 7a-7j. On the other hand, Ru catalysts 7j, 7i,and 7f have good activity and much better than 10a-d.

Most of Ru catalysts 9a-j are soluble in DCM, DCE, CHCl₃, Ether, andother solvents, but almost insoluble in MeOH, EtOH, and other alcohols,which provides a recyclable method to recover the Ru catalysts 9a-j byprecipitating the Ru catalysts in MeOH or EtOH. On the other hand, whenthe metathesis products are soluble in MeOH or EtOH, the Ru catalystscould be removed by precipitating the reaction mixture in MeOH. However,the Ru catalyst 7f with 5-aminocarbonyl-2-isopropylbenzylidene ligand isnot only soluble in DCM, DCE, CHCl₃, Ether, and other solvents, but alsosuloble in MeOH, EtOH, and other alcohols, which suggests that it isbetter to use Ru catalyst 7f for metathesis reactions when themetathesis products are insoluble and precipitated in MeOH or EtOH, sothe alcohol-soluble Ru catalyst 7f is easily removed in alcohol solutionby filtration.

Finally, the resin-linked Ru catalysts 18a and 19a are not only highlyactive, but also recyclable and reusable efficiently for metathesisreactions for 3-6 times.

EXAMPLES

General. Infrared (IR) spectra were recorded on a Fourier TransformAVATAR™ 360 E.S.P™ spectrophotometer (Unit: cm⁻¹). Bands arecharacterized as broad (br), strong (s), medium (m), and weak (w). ¹HNMR spectra were recorded on a Varian-400 (400 MHz) spectrometer.Chemical shifts are reported in ppm from tetramethylsilane with thesolvent resonance as the internal standard (CDCl₃: 7.26 ppm). Data arereported as follows: chemical shift, multiplicity (s=singlet, d=doublet,t=triplet, q=quartet, br=broad, m=multiplet), coupling constants (Hz),integration, and assignment. ¹⁹F and ³¹P NMR spectra were recorded on aVarian-400 (400 MHz) and Gemini-2000 (300 MHz) spectrometers. Thechemical shifts of the fluoro resonances were determined relative totrifluoroacetic acid as the external standard (CF₃CO₂H: 0.00 ppm), andthe chemical shifts of the phosphorus resonances were determinedrelative to phosphoric acid as the external standard (H₃PO₄: 0.00 ppm).Mass spectra were obtained at Thermo Finnigan LCQ Advantage. Unlessotherwise noted, all reactions were conducted in oven—(135° C.) andflame-dried glassware with vacuum-line techniques under an inertatmosphere of dry Ar. THF and Et₂O were distilled from sodium metaldried flask, DCM, pentane, and hexanes were distilled from calciumhydride. Different substituted 2-alkoxystyrene ligands were preparedaccording to literature procedures as shown in Schemes 1-3. Mostchemicals were obtained from commercial sources and confirmed to be usedwithout any quality problems. All product purification was performedwith silica gel 60 (200-400 mesh) obtained from Qingdao Haiyang ChemicalCo. General procedure is described in example 1 for preparation ofdifferent substituted 2-alkoxystyrene ligands 4a-4i, 6a-6n, and 8a-8j byortho-vinylation reaction (Yamaguchi et al, J. Org. Chem. 1998, 63,7298-7305, synthesis in 50 mmol scale for ortho-vinylation), followed byetherification of 2-hydroxystyrene with alkyliodide or alkylbromide (10mmol scale for etherification) in DMF in the presence of K₂CO₃ at 45-65°C. General procedure is described in example 2 for synthesis of Rucomplexes 5a-5i, 7a-7n, and 9a-9j by reaction of Ru complex 1a or 1bwith different substituted 2-alkoxystyrene ligands 4a-4i, 6a-6n, and8a-8j, respectively (Hoveyda et al, J. Am. Chem. Soc. 1999, 121,791-799, and J. Am. Chem. Soc. 2000, 122, 8168-8179, synthesis in 0.5mmol scale). However, based on the general literature procedure as thefollowing Example 2, there is no any product of Ru complex 5a-5iobtained by TLC or flash column. It is observed that the decompositiontakes place during the preparation of complexes 5a-5i, which means thatthe listed Ru complexes 5a-5i are very unstable and impossible to beused as metathesis catalysts.

Example 1 Synthesis of 1-chloro-2-isopropoxy-3-vinyl-benzene (4a)

Preparation of 2-chloro-6-vinylphenol: Ethyne was bubbled into adichloroethane (DCE, 200 mL) solution of SnCl₄ (25 mL, 0.2 mol) and Bu₃N(50 mL, 0.2 mol) at −50° C. for 45 min under an Ar atmosphere, followedby adding 2-chlorophenol (6.50 g, 50 mmol). After finishing theaddition, the mixture was heated at 60° C. for 1 hr. K₂CO₃ (13.8 g) andmethanol (100 mL) were added, and refluxing for another 30 min. Afterthe reaction was completed, the reaction mixture was poured into amixture of ethyl ether and saturated aq KHSO₄. The precipitatedbyproducts were filtered through Celite, and the organic materials wereextracted with ether three times. The combined organic layers werewashed with brine and dried over Na₂SO₄, then ether was removed byrotovap, 2-chloro-6-vinylphenol was obtained by flash chromatography,4.83 g of ortho-vinylphenol was obtained (yield: 63%, purity: 97%). Thepurified ortho-vinylation product could be directly used for nextetherification with isopropyliodide (iPrI) in 10 mmol scale.

Preparation of 1-Chloro-2-isopropoxy-3-vinyl-benzene (4a):2-chloro-6-vinylphenol (1.55 g, 10 mmol) and 2-iodopropance (1.5 ml, 15mmol, 1.5 equiv) were dissolved in DMF, followed by adding K₂CO₃ (3.9 g,30 mmol) into DMF solution, then heated at 60° C. overnight.etherification was monitored by TLC and HPLC until completed. Themixture was diluted with Et₂O (250 mL), and washed with water (2×200mL). The aqueous layer was extracted twice with Et₂O (150 mL), and thecombined organic layers were washed with brine, and dried over MgSO₄.The product was purified by flash column (Hexanes:Et₂O=6:1) to offer1.69 g of product 4a (Yield: 82%, purity: 98%). ¹HNMR (CDCl₃: δ=7.26ppm): 7.42 (dd, 1H, J=1.56, 7.82 Hz), 7.29 (dd, 1H, J=1.56, 7.83 Hz),7.02 (m, 2H), 5.73 (d, 1H, J=17.60 Hz), 5.56 (d, 1H, J=11.34 Hz), 4.43(m, 1H), 1.32 (d, 6H, J=6.26 Hz). (M+H⁺): m/z calculated: 197.1. found:197.1.

Example 2 Synthesis of Ruthenium Complex with1-Chloro-2-isopropoxy-3-vinyl-benzene (5a)

(H₂IMES)(PCy₃)Cl₂Ru═CHPh (formula 1b) (450 mg, 0.5 mmol) and CuCl (135mg, 1.25 mmol, 2.5 eq) were added into a 100 mL round-bottom flask underan Ar in a glove box and dissolved in DCM (15 mL), and1-Chloro-2-isopropoxy-3-vinyl-benzene (4a, 105 mg, 0.5 mmol, 1.0 eq) wasadded into the red solution at 20-25° C. The reaction was completed andno any 1b left by TLC in 30 min. However, the reaction mixture was darkbrown instead of green color for the product of complex 5a, which meansthat no any green spot of complex 5a was formed and observed by TLC.

Example 3 Synthesis of Ruthenium Complex with4-Chloro-1-isopropoxy-2-vinyl-benzene (7a)

(H₂IMES)(PCy₃)Cl₂Ru═CHPh (formula 1b) (450 mg, 0.5 mmol) and CuCl (135mg, 1.25 mmol, 2.5 eq) were added into a 100 mL round-bottom flask underan Ar in a glove box and dissolved in DCM (15 mL), and4-Chloro-1-isopropoxy-2-vinyl-benzene (6a, 105 mg, 0.5 mmol, 1.0 eq) wasadded into the red solution at 20-25° C. The reaction was completed andno any 1b left by TLC in 30 min. The reaction mixture was green colorfor the product of complex 7a, then filtered. The filtrate wasconcentrated and purified by flash column eluting with a gradientsolvent (Pentane/DCM 2/1 to DCM). Concentration of the product fractionsin vacuum resulted in a deep-green solid, which was washed withmethanol, and dried under vacuum to give 223 mg of a greenmicrocrystalline solid (68% yield). The green product was confirmed by¹HNMR and MS analysis.

¹HNMR (400 MHz, CDCl₃) δ=16.44 (s, 1H, Ru═CH), 7.46 (dd, 1H, J=2.74,9.00 Hz), 7.08 (s, 4H), 6.89 (d, 1H, J=2.74 Hz), 6.72 (d, 1H, J=8.61Hz), 4.85 (m, 1H), 2.46 (s, 12H), 2.41 (s, 6H), 1.25 (d, 6H, J=6.26 Hz).(M+H⁺): m/z calculated: 661.1. found: 661.2.

Example 4 Synthesis of Ru Complex with1,2-Dichloro-4-isopropoxy-5-vinyl-benzene (7b)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.203 mg of green solid product was obtained (56% yield).

¹HNMR (400 MHz, CDCl₃): δ=16.37 (s, 1H, Ru═CH), 7.07 (s, 4H), 6.98 (s,1H), 6.88 (s, 1H), 4.82 (m, 1H), 4.18 (s, 4H), 2.45 (s, 12H), 2.40 (s,6H), 1.25 (d, 6H, J=6.26 Hz). (M+H⁺): m/z calculated: (M+H⁺): m/zcalculated: 695.1. founded: 695.2.

Example 5 Synthesis of Ru Complex with4-Fluoro-1-isopropoxy-2-vinyl-benzene (7c)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.198 mg of green solid product was obtained (63% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.49 (s, 1H, Ru═CH), 7.26-7.20 (m, 1H), 7.13(s, 4H), 6.71 (dd, J=3.0, 9.0 Hz, 1H), 6.62 (dd, J=3.1, 7.9 Hz, 1H),4.85-4.81 (m, 1H, OCHMe₂), 4.19 (s, 4H), 2.47 (s, 12H), 2.27 (s, 6H),1.26 (d, J=6.2 Hz, 6H). ¹⁹F-NMR (300 MHz, CDCl₃): δ=−41.66.

Example 6 Synthesis of Ru Complex with1,2-Difluoro-4-isopropoxy-5-vinyl-benzene (7d)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.173 mg of green solid product was obtained (51% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.21 (s, 1H, Ru═CH), 7.07 (s, 4H), 6.72 (t,J=9.4 Hz, 1H), 6.65-6.59 (m, 1H), 4.78-4.74 (m, 1H, OCHMe₂), 4.17 (s,4H), 2.45 (s, 12H), 2.40 (s, 6H), 1.23 (d, J=6.1 Hz, 6H).

Example 7 Synthesis of Ru Complex with1,5-Difluoro-3-isopropoxy-2-vinyl-benzene (7e)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.152 mg of green solid product was obtained (44% yield).

¹H NMR (300 MHz, CDCl₃): δ=16.72 (s, 1H), 7.27 (s, 1H), 7.06 (s, 4H),6.32 (t, 1H, J=10.15 Hz)/6.36-6.28 (m, 2H), 4.80 (m, 1H), 4.18 (s, 4H),2.47 (s, 12H), 2.37 (s, 6H), 1.28 (d, 6H, J=6.23 Hz).

Example 8 Synthesis of Ru Complex with 4-Isopropoxy-3-vinyl-benzamide(7f)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.213 mg of green solid product was obtained (63% yield).

¹H-NMR (300 MHz, CDCl₃): δ=16.55 (s, 1H, Ru═CH), 7.93 (d, J=6.9 Hz, 1H),7.34 (d, J=1.4 Hz, 1H), 7.09 (s, 4H), 6.81 (d, J=8.8 Hz, 1H), 4.94-4.90(m, 1H, OCHMe₂), 4.19 (s, 4H), 2.47 (s, 12H), 2.42 (s, 6H), 1.27 (d,J=5.9 Hz, 6H).

Example 9 Synthesis of Ru Complex with 4-Isopropoxy-3-vinyl-benzoic acidmethyl ester (7g)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.197 mg of green solid product was obtained (56% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.45 (s, 1H, Ru═CH), 8.20 (dd, J=2.2, 8.8 Hz,1H), 7.63 (d, J=2.2 Hz, 1H), 7.09 (s, 4H), 6.84 (d, J=8.8 Hz, 1H),4.97-4.93 (m, 1H, OCHMe₂), 4.20 (s, 4H), 3.90 (s, 3H), 2.47 (s, 12H),2.43 (s, 6H), 1.29 (d, J=6.2 Hz, 6H).

Example 10 Synthesis of Ru Complex with4-Isopropoxy-3-vinyl-benzaldehyde (7h)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.178 mg of green solid product was obtained (52% yield). ¹HNMR (300 MHz,CDCl₃): δ=16.61 (s, 1H, Ru═CH), 9.89 (s, 1H, CHO), 8.17 (dd, J=2.2, 8.8Hz, 1H), 7.44 (d, J=2.2 Hz, 1H), 7.09 (s, 4H), 6.95 (d, J=8.8 Hz, 1H),5.01-4.97 (m, 1H, OCHMe₂), 4.19 (s, 4H), 2.47 (s, 12H), 2.43 (s, 6H),1.31 (d, J=6.3 Hz, 6H).

Example 11 Synthesis of Ru Complex with1-(4-Isopropoxy-3-vinyl-phenyl)-ethanone (7i)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.189 mg of green solid product was obtained (55% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.49 (s, 1H, Ru═CH), 8.16 (dd, J=1.9, 8.8 Hz,1H), 7.53 (d, J=1.9 Hz, 1H), 7.09 (s, 4H), 6.87 (d, J=8.8 Hz, 1H),4.98-4.94 (m, 1H, OCHMe₂), 4.21 (s, 4H), 2.52 (s, 3H), 2.48 (s, 12H),2.43 (s, 6H), 1.29 (d, J=5.9 Hz, 6H).

Example 12 Synthesis of Ru Complex with(4-Isopropoxy-3-vinyl-phenyl)-phenyl-methanone (7j)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.199 mg of green solid product was obtained (53% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 8.10 (dd, J=1.8, 8.4 Hz,1H), 7.75-7.72 (m, 2H), 7.63-7.58 (m, 1H), 7.52-7.47 (m, 2H), 7.35 (d,J=1.8 Hz, 1H), 7.02 (s, 4H), 6.92 (d, J=8.4 Hz, 1H), 5.01-4.97 (m, 1H,OCHMe₂), 4.19 (s, 4H), 2.46 (s, 12H), 2.24 (s, 12H), 1.29 (d, J=8.1 Hz,6H).

Example 13 Synthesis of Ru Complex with4-Isopropoxy-N,N-dimethyl-3-vinyl-benzenesulfonamide (7k)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.247 mg of green solid product was obtained (66% yield).

¹HNMR (400 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 7.93 (dd, J=2.2, 8.8 Hz,1H), 7.32 (d, J=2.2 Hz, 1H), 7.08 (s, 4H), 6.91 (d, J=8.8 Hz, 1H),4.97-4.94 (m, 1H, OCHMe₂), 4.21 (s, 4H), 2.71 (s, 6H), 2.46 (s, 12H),2.40 (s, 6H), 1.29 (d, J=5.9 Hz, 6H).

Example 14 Synthesis of Ru Complex withBis-(4-Isopropoxy-3-vinyl-phenyl)-sulfone (7m)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.193 mg of green solid product was obtained (56% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.42 (s, 2H, Ru═CH), 7.87 (dd, J=2.2, 8.8 Hz,2H), 7.53 (d, J=2.2 Hz, 2H), 7.07 (s, 8H), 6.87 (d, J=8.8 Hz, 2H),4.96-4.92 (m, 2H, OCHMe₂), 3.15 (s, 8H), 2.45 (s, 24H), 2.41 (s, 12H),1.27 (d, J=5.9 Hz, 12H).

Example 15 Synthesis of Ru Complex withBis-(4-isopropoxy-3-vinyl-phenyl)-methanone (7n)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.171 mg of green solid product was obtained (52% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.44 (s, 2H, Ru═CH), 7.93 (dd, J=2.0, 8.4 Hz,2H), 7.30 (d, J=2.0 Hz, 2H), 7.03 (s, 8H), 6.88 (d, J=8.4 Hz, 2H),5.01-4.97 (m, 2H, OCHMe₂), 4.19 (s, 8H), 2.47 (s, 24H), 2.26 (s, 12H),1.33 (d, J=6.2 Hz, 12H).

Example 16 Synthesis of Ru Complex with1-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-1H-pyrrole (9a)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.211 mg of green solid product was obtained (62% yield).

¹HNMR (400 MHz, CDCl₃): δ=16.36 (s, 1H, Ru═CH), 7.98 (dd, 1H, J=2.35,8.81 Hz), 7.40 (d, 1H, J=2.35 Hz), 7.10 (m, 2H), 7.08 (s, 4H), 6.87 (d,1H, J=9.00 Hz), 6.31 (m, 2H), 4.92 (m, 1H, OCHMe₂), 4.20 (s, 4H), 2.44(s, 18H), 1.13 (d, 6H, J=5.87 Hz).

Example 17 Synthesis of Ru Complex with4-Isopropoxy-3-methoxy-N,N-dimethyl-5-vinyl-benzenesulfonamide (9b)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.158 mg of green solid product was obtained (41% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.34 (s, 1H, Ru═CH), 7.45 (d, 1H, J=1.83 Hz),7.17 (s, 4H), 6.92 (d, 1H, J=2.20 Hz), 5.80 (m, 1H, OCHMe₂), 4.20 (s,4H), 3.81 (s, 3H), 2.73 (s, 6H), 2.47 (s, 12H), 2.40 (s, 6H), 1.31 (d,6H, J=6.22 Hz).

Example 18 Synthesis of Ru Complex with4-(2-Methoxy-ethoxy)-N,N-dimethyl-3-vinyl-benzenesulfonamide (9c)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.165 mg of green solid product was obtained (44% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.37 (s, 1H, Ru═CH), 7.94 (dd, 1H, J=2.20,8.79 Hz), 7.29 (d, 1H, J=2.20 Hz), 7.09 (s, 4H), 7.06 (d, 1H, J=8.79Hz), 4.34 (t, 2H, J=5.85 Hz), 4.18 (s, 4H), 3.61 (t, 2H, J=5.94 Hz),3.13 (s, 3H), 2.70 (s, 6H), 2.47 (s, 12H), 2.42 (s, 6H).

Example 19 Synthesis of Ru Complex with1-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-pyrrolidine (9d)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.195 mg of green solid product was obtained (54% yield).

¹HNMR (400 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 7.97 (dd, 1H, J=2.35,8.61 Hz), 7.37 (d, 1H, J=1.96 Hz), 7.08 (s, 4H), 6.90 (d, 1H, J=9.00Hz), 4.95 (m, 1H, OCHMe₂), 4.21 (s, 4H), 3.21 (m, 4H), 2.46 (s, 12H),2.41 (s, 6H), 1.83 (m, 4H), 1.29 (d, 6H, J=5.87 Hz).

Example 20 Synthesis of Ru Complex with4-sec-Butoxy-N,N-dimethyl-3-vinyl-benzenesulfonamide (9e)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.176 mg of green solid product was obtained (47% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.40 (s, 1H, Ru═CH), 7.93 (dd, 1H, J=2.20,8.79 Hz), 7.33 (d, 1H, J=2.19 Hz), 7.08 (s, 4H), 6.87 (d, 1H, J=8.79Hz), 4.66 (m, 1H, OCHMe₂), 4.21 (s, 4H), 2.72 (s, 6H), 2.47 (s, 12H),2.42 (s, 6H), 1.45 (m, 2H), 1.27 (d, 3H, J=5.86 Hz), 0.80 (t, 3H, J=7.69Hz).

Example 21 Synthesis of Ru Complex with1-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-pyrrolidine-2-carboxylic acidmethyl ester (9f)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.196 mg of green solid product was obtained (52% yield).

¹HNMR (400 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 8.04 (dd, 1H, J=1.95,8.60 Hz), 7.41 (d, 1H, J=2.35 Hz), 7.10 (s, 4H), 6.89 (d, 1H, J=8.61Hz), 4.95 (m, 1H, OCHMe₂), 4.24 (m, 1H), 4.21 (s, 4H), 3.66 (s, 3H),3.48 (m, 1H), 3.24 (m, 1H), 2.46 (s, 12H), 2.42 (s, 6H), 1.81-2.13 (m,5H), 1.28 (d, 6H, J=5.87 Hz).

Example 22 Synthesis of Ru Complex with1-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-piperidine-4-carboxylic acidmethyl ester (9g)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.226 mg of green solid product was obtained (55% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 7.90 (dd, 1H, J=2.20,8.79 Hz), 7.30 (d, 1H, J=1.83 Hz), 7.08 (s, 4H), 6.90 (d, 1H, J=8.79Hz), 4.95 (m, 1H, OCHMe₂), 4.21 (s, 4H), 3.69 (s, 3H), 3.63 (m, 1H),2.47 (s, 12H), 2.41 (s, 6H), 2.09 (dd, 4H, J=3.29, 13.55 Hz), 1.85 (m,4H), 1.30 (d, 6H, J=6.22 Hz).

Example 23 Synthesis of Ru Complex with4-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-morpholine (9h)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.193 mg of green solid product was obtained (52% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.31 (s, 1H, Ru═CH), 7.83 (dd, 1H, J=2.19,8.79 Hz), 7.24 (d, 1H, J=2.20 Hz), 7.00 (s, 4H), 6.85 (d, 1H, J=8.79Hz), 4.89 (m, 1H, OCHMe₂), 4.13 (s, 4H), 3.68 (t, 4H, J=4.77 Hz), 2.95(t, 4H, J=4.76 Hz), 2.39 (s, 12H), 2.33 (s, 6H), 1.23 (d, 6H, J=6.23Hz).

Example 24 Synthesis of Ru Complex with4-Isopropoxy-N,N-dipropyl-3-vinyl-benzenesulfonamide (9i)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.216 mg of green solid product was obtained (54% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.36 (s, 1H, Ru═CH), 7.90 (dd, 1H, J=2.20,8.79 Hz), 7.32 (d, 1H, J=2.20 Hz), 7.09 (s, 4H), 6.88 (d, 1H, J=8.78Hz), 4.66 (m, 1H, OCHMe₂), 4.21 (s, 4H), 3.77 (t, 4H, J=4.76 Hz), 3.03(t, 4H, J=4.84), 2.47 (s, 12H), 2.42 (s, 6H), 1.38 (m, 2H), 1.30 (d, 3H,J=9.15 Hz), 0.90 (t, 3H, J=7.69 Hz).

Example 25 Synthesis of Ru Complex with4-(4-sec-Butoxy-3-vinyl-benzenesulfonyl)-morpholine (9j)

The synthetic procedure is the same as in Example 3 in 0.5 mmol scale.186 mg of green solid product was obtained (47% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.36 (s, 1H, Ru═CH), 7.90 (dd, 1H, J=2.20,8.79 Hz), 7.32 (d, 1H, J=2.20 Hz), 7.09 (s, 4H), 6.88 (d, 1H, J=8.78Hz), 4.66 (m, 1H, OCHMe₂), 4.21 (s, 4H), 3.77 (t, 4H, J=4.76 Hz), 3.03(t, 4H, J=4.84), 2.47 (s, 12H), 2.42 (s, 6H), 1.48 (m, 2H), 1.30 (d, 3H,J=9.15 Hz), 0.80 (t, 3H, J=7.69 Hz).

Example 26 Synthesis of1-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-piperidine-4-carboxylic acid(15)

Compound 8g (2.0 g, 5.0 mmol) was dissolved in 30 mL MeOH and 15 mLwater, and NaOH (1.0 g, 25.0 mmol) was added, the reaction mixture wasstirred at 20° C. for 4.0 hrs. The solvent was removed rotovap, 30 mLwater was added and the mixture was extracted with ether (2×70 mL) andthe aqueous phase was adjusted to pH=2-3, then extracted with EtOAc(3×60 mL) and the combined organic phase was washed with brine, driedand concentrated. 1.7 g of product 15 was obtained in 92% of yield(Purity: 98%).

¹HNMR (300 MHz, CDCl₃): δ=7.80 (d, 1H, J=2.47 Hz), 7.60 (dd, 1H, J=2.47,8.79 Hz), 7.00 (dd, 1H, J=11.26, 17.85 Hz), 6.95 (d, 1H, J=8.79 Hz),5.81 (dd, 1H, J=1.1, 17.58 Hz), 5.39 (dd, 1H, J=1.1, 11.27 Hz), 4.66 (m,1H), 3.64 (m, 2H), 2.43 (m, 2H), 2.26 (m, 1H), 2.00 (m, 2H), 1.87 (m,2H), 1.42 (d, 6H, J=6.05 Hz). (M+H⁺): m/z calculated: 352.1. found:352.1.

Example 27 Synthesis of Resin Bounded Ru Catalyst (19a)

To the solution of compound 15 (0.80 g, 2.3 mmol) in DCM (20 mL) wasadded HOBt (0.32 g, 2.4 mmol), then DCC (0.52 g, 2.5 mmol) in DCM (8 mL)was added dropwise, the resulting mixture was stirred overnight.Filtrated and concentrated. 1.20 g of product was obtained, and added toa DMF solution (15 mL) of polystyrene resin (0.85 g, 1.44 mmol, 1.0 eq.)and DMAP (0.2 g, 1.44 mmol, 1.0 eq.). The reaction mixture was shakedovernight. After the coupling was completed, the resin was washed withDMF (20 mL×3), THF (20 mL×3), DCM (20 mL×3), 1/1 DCM/Et₂O (20 mL×1),Et₂O (20 mL×3) and dried under reduced pressure to offer 0.98 g ofproduct 16a.

To a solution of 16a (0.90 g, 1.5 mmol, 1.0 eq.) in DCM (15 mL),(PPh₃)₂Cl₂Ru═CHPh (1.95 g, 2.25 mmol, 1.5 eq.) and CuCl (0.39 g, 3.75mmol, 2.5 eq.) were added under Ar. The solution was agitated for 2 hrsto offer product 17a, followed by adding PCy3 (2.0 eq) in DCM (5 mL) at−60° C. for 30 min, then kept agitating overnight. The resin was washedwith DMF (20 mL×3), THF (20 mL×3), DCM (20 mL×3), 1/1 DCM/Et₂O (20mL×1), Et₂O (20 mL×3) and dried to offer 1.24 g of product 18a.

To a solution of 18a (0.90 g, 1.5 mmol, 1.0 eq.) in DCM (5 mL) was addedinto another ligand H₂IMes(H)(CCl₃) solution in toluene (10 mL) at 80°C. with agitation and kept overnight until the reaction was completed.The resin was washed with DMF (20 mL×3), THF (20 mL×3), DCM (20 mL×3),1/1 DCM/Et₂O (20 mL×1), Et₂O (20 mL×3) and dried to offer 1.11 g ofproduct 19a.

IR: 3454.20 (w), 2921.47 (br), 1733.20 (m), 1613.66 (s), 1112.85 (m).

Example 28 Synthesis of Resin Bounded Ru Catalyst (19b)

The synthetic procedure is the same as in Example 27 starting with 0.8 gof 15 and PEG800 (1.0 eq) to obtain 16b, followed by reacting with(PPh₃)₂Cl₂Ru═CHPh (1. eq) and CuCl (3.0 eq) in DCM for 2 hr to form 17b,then PCy3 (2.0 eq) was added to offer 18b. Finally, 18b (0.50 g) in DCE(5 mL) was added into another prepared H₂IMes carbene solution intoluene (10 mL), and kept shaking overnight, then purified by flashcolumn to obtain 0.36 g of product 19b as dark green solid.

¹HNMR (300 MHz, CDCl₃): δ=16.38 (s, 1H, Ru═CH), 7.92 (dd, 1H, J=2.20,8.79 Hz), 7.30 (d, 1H, J=1.83 Hz), 7.08 (s, 4H), 6.90 (d, 1H, J=8.79Hz), 4.95 (m, 1H, OCHMe₂), 4.21 (s, 4H), 3.70-1.30 (broad peaks, PEGproton peaks overlapped).

IR: 3441.82 (w), 2925.79 (m), 1732.10 (s), 1633.66 (s), 1263.83 (s),1106.00 (m).

Example 29 Synthesis of 2-Isopropoxy-5-chlorobenzaldehydep-Toluenesulfonydrazone (27a)

A suspension of p-toluenesulfonyl hydrazide (26.5 g, 142 mmol, 1.0 eq.)in methanol (100 mL) was treated rapidly with aldehyde 26a (29 g, 145mmol, 1.0 eq.) under agitation. After 30 min, the solution was cooled to0-5° C., and product was precipitated, filtered, and dried to offer awhite solid product 27a (50.4 g, 96% yield, purity: 99%).

¹HNMR (300 MHz, CDCl₃): δ=8.08 (d, J=1.6 Hz, 1H), 7.88 (d, J=8.5 Hz,1H), 7.77 (d, J=2.8 Hz, 2H), 7.33 (d, J=7.9 Hz, 1H), 7.25 (dd, J=2.8,7.9 Hz, 1H), 6.79 (d, J=8.8 Hz, 2H), 4.52-4.48 (m, 1H, OCHMe₂), 2.42 (s,3H), 1.29 (d, J=6.1 Hz, 6H). (M+H⁺): m/z calculated: 366.1. found:366.1.

Example 30 Synthesis of Ru Complex with PPh₃ and5-Chloro-2-isopropoxybenzylidene Ligand (28a)

27a (10 g, 27.3 mmol, 1.0 eq) was treated with NaOEt (3.9 g, 54.6 mmol,2.0 eq.) in EtOH (100 mL) and heated to 60° C. After the reaction wascompleted in 50 min, ice water (120 mL) was added, and extracted withpentane (3×100 mL). The combined organic solution was washed withsaturated Na₂CO₃ (50 mL×2), brine (50 mL×2), and dried with Na₂SO₄, thenconcentrated at 0-5° C. to about 20 mL, followed by adding theconcentrated diazo solution into the RuCl₂(PPh₃)₃ (7.0 g, 7.3 mmol, 1.0eq.) solution in CH₂Cl₂ (50 mL) at −78° C. After 10-15 min, the solutionwas warmed up to 20° C., and CuCl (2.2 g, 21.9 mmol, 3.0 eq.) was addedto react for another 15 min, then the reaction mixture was filtered, andthe filtrate was concentrated and purified by flash column eluting witha gradient solvents (2:1 hexane/DCM to DCM). Concentration of theproduct fractions offers a deep-green solid, which was washed withhexanes, dried under vacuum to give 2.9 g of 28a as a redmicrocrystalline solid (64% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.60 (d, J_(PH)=6.8 Hz, 1H, Ru═CH), 7.63-7.44(m, 17H), 7.14 (d, J=8.5 Hz, 1H), 5.41-5.38 (m, 1H, OCHMe₂), 1.90 (d,J=6.4 Hz, 6H). ³¹P-NMR (121 MHz, CDCl₃): δ=56.350 (s, PPh₃).

Example 31 Synthesis of Ru Complex with H₂IMes and5-Chloro-2-isopropoxybenzylidene Ligand (30a)

H₂IMes(H)(CCl₃) (1.38 g, 3.24 mmol, 2.0 eq.) and 28a (1.0 g, 1.62 mmol,1.0 eq.) was dissolved in toluene (10 mL) and heated to 80° C. for 2.0h, then cooled. The solution was purified by flash column eluting with2:1 hexane/DCM. Concentration of the product fractions in vacuumresulted a deep-green solid, which was washed with methanol and hexanes,dried under vacuum to offer 533 mg of product 30a as a greenmicrocrystalline solid (51% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.46 (s, 1H, Ru═CH), 7.46 (dd, J=2.6, 8.7 Hz,1H), 7.08 (s, 4H), 6.89 (d, J=2.6 Hz, 1H), 6.72 (d, J=8.7 Hz, 1H),4.88-4.82 (m, 1H, OCHMe₂), 4.18 (s, 4H), 2.46 (s, 12H), 2.41 (s, 6H),1.25 (d, J=6.2 Hz, 6H).

Example 32 Synthesis of 2-Isopropoxy-5-fluorobenzaldehydep-Toluenesulfonydrazone (27b)

The synthetic procedure is the same as in Example 29 for preparation of27a. The yield for 27b is 95%, and the NMR results for 27b are asfollows:

¹HNMR (300 MHz, CDCl₃): δ=8.10 (d, J=1.9 Hz, 1H), 7.97 (s, 1H), 7.87 (d,J=8.2 Hz, 2H), 7.50 (dd, J=3.0, 9.0 Hz, 1H), 7.32 (d, J=8.2 Hz, 2H),7.02-6.95 (m, 1H), 6.80 (dd, J=4.4, 9.1 Hz, 1H), 4.53-4.42 (m, 1H), 2.41(s, 3H), 1.29 (d, J=6.1 Hz, 6H). ¹⁹F-NMR (282 MHz, CDCl₃): δ=−40.25.(M+H⁺): m/z calculated: 350.1. found: 350.2.

Example 33 Synthesis of Ru Complex with PPh₃ and5-Fluoro-2-isopropoxybenzylidene Ligand (28b)

The synthetic procedure is the same as in Example 30. The yield for 28bis 57%, and the NMR results for 28b are as follows:

¹HNMR (300 MHz, CDCl₃): δ=16.59 (d, J_(PH)=6.6 Hz, 1H, Ru═CH), 7.55-7.26(m, 17H), 7.09 (dd, J=3.9, 9.0 Hz, 1H), 5.37-5.32 (m, 1H, OCHMe₂), 1.86(d, J=6.3 Hz, 6H). ¹⁹F-NMR (282 MHz, CDCl₃): δ=−40.48. ³¹P-NMR (121 MHz,CDCl₃): δ=56.19 (s, PPh₃).

Example 34 Synthesis of Ru Complex with H₂IMes and5-Fluoro-2-isopropoxybenzylidene Ligand (30b)

The synthetic procedure is the same as in Example 31. The yield for 30bis 42%, and the NMR results for 30b are as follows:

¹HNMR (300 MHz, CDCl₃): δ=16.49 (s, 1H, Ru═CH), 7.26-7.20 (m, 1H), 7.13(s, 4H), 6.71 (dd, J=3.0, 9.0 Hz, 1H), 6.62 (dd, J=3.1, 7.9 Hz, 1H),4.85-4.81 (m, 1H, OCHMe₂), 4.19 (s, 4H), 2.47 (s, 12H), 2.27 (s, 6H),1.26 (d, J=6.2 Hz, 6H). ¹⁹F-NMR (282 MHz, CDCl₃): δ=−41.663.

Example 35 Synthesis of 2-Isopropoxy-5-dimethylaminosulfonylbenzaldehydep-Toluenesulfonydrazone (32a)

The synthetic procedure is the same as in Example 29 for preparation of27a. The yield for 32a is 96%, and the NMR result of 32a is as follows:

¹HNMR (300 MHz, CDCl₃): δ=8.14-8.11 (m, 2H), 7.87 (d, J=8.2 Hz, 2H),7.71-7.67 (m, 1H), 7.30 (d, J=8.2 Hz, 2H), 6.94 (d, J=8.8 Hz, 1H),4.68-4.60 (m, 1H, OCHMe₂), 2.70 (s, 6H), 2.40 (s, 3H), 1.35 (d, J=6.0Hz, 6H). (M+H⁺): m/z calculated: 439.1. found: 439.2.

Example 36 Synthesis of Ru Complex with PPh₃ and2-Isopropoxy-5-dimethylaminosulfonylbenzylidene Ligand (33a)

The synthetic procedure is the same as in Example 30 for preparation of28a. The yield for 33a is 63%, and the NMR results of 33a are asfollows:

¹HNMR (300 MHz, CDCl₃): δ=16.69 (d, J_(PH)=6.9 Hz, 1H, Ru═CH), 8.09-8.06(m, 2H), 7.57-7.43 (m, 16H), 7.34 (d, J=9.0 Hz, 1H), 5.53-5.49 (m, 1H,OCHMe₂), 2.82 (s, 6H), 1.94 (d, J=6.4 Hz, 6H). ³¹P-NMR (121 MHz, CDCl₃)δ=56.05 (s, PPh₃).

Example 37 Synthesis of Ru Complex with PCy₃ and2-Isopropoxy-5-dimethylaminosulfonylbenzylidene Ligand (34a)

33a (4.0 g, 5.8 mmol, 1.0 eq.) was dissolved in CH₂Cl₂ (50 mL) under Ar,then tricyclohexylphosphine (PCy₃, 3.25 g, 11.6 mmol, 2.0 eq.) wasadded. The solution was stirred at 20° C. for 0.5 h, then concentratedand purified by flash column eluting with a gradient solvent (2:1petroleum ether/DCM to DCM). Concentration in vacuum resulted a brownsolid, which was washed with methanol, dried under vacuum resulted 2.76g of product 34a as a purple microcrystalline solid (67% yield).

¹HNMR (300 MHz, CDCl₃): δ=17.40 (d, J_(PH)=4.3 Hz, 1H, Ru═CH), 8.13 (d,J=2.1 Hz, 1H), 8.04 (dd, J=2.1, 8.6 Hz, 1H), 7.21 (d, J=8.6 Hz, 1H),5.36-5.30 (m, 1H, OCHMe₂), 2.79 (s, 6H), 2.39-1.28 (m, 39H). ³¹P-NMR(121 MHz, CDCl₃): δ=55.91 (s, PCy₃).

Example 38 Synthesis of Ru Complex with H₂IMes and2-Isopropoxy-5-dimethylaminosulfonylbenzylidene Ligand (7k)

H₂IMes(H)(CCl₃) (1.4 g, 3.2 mmol, 2.0 eq.) and 34a (1.2 g, 1.6 mmol, 1.0eq.) was dissolved in toluene (10 mL) and heated to 80° C. for 1.5 h,then cooled. The solution was purified by flash column eluting with 2:1hexane/DCM. Concentration of the product fractions in vacuum resulted adeep-green solid, which was washed with methanol and hexanes, driedunder vacuum to offer 685 mg of product 7k as a green microcrystallinesolid (58% yield).

¹HNMR (300 MHz, CDCl₃): δ=16.39 (s, 1H, Ru═CH), 7.93 (dd, J=2.2, 8.8 Hz,1H), 7.32 (d, J=2.2 Hz, 1H), 7.08 (s, 4H), 6.91 (d, J=8.8 Hz, 1H),4.97-4.94 (m, 1H, OCHMe₂), 4.21 (s, 4H), 2.71 (s, 6H), 2.46 (s, 12H),2.40 (s, 6H), 1.29 (d, J=5.9 Hz, 6H).

Example 39 Synthesis of 2-Isopropoxy-5-nitrobenzaldehydep-Toluenesulfonydrazone (32b)

The synthetic procedure is the same as in Example 29 for preparation of27a. The yield for 32b is 93%, and the NMR result of 32b is as follows:

¹HNMR (300 MHz, CDCl₃): δ=8.62 (d, J=3.0 Hz, 1H), 8.18 (dd, J=3.0, 9.4Hz, 1H), 8.16 (s, 1H), 7.91 (d, J=8.3 Hz, 2H), 7.36 (d, J=8.3 Hz, 2H),6.91 (d, J=9.4 Hz, 1H), 4.74-4.66 (m, 1H, OCHMe₂), 2.42 (s, 3H), 1.38(d, J=6.0 Hz, 6H). (M+H⁺): m/z calculated: 378.1. found: 378.1.

Example 40 Synthesis of Ru Complex with PPh₃ and2-Isopropoxy-5-nitrobenzylidene Ligand (33b)

The synthetic procedure is the same as in Example 30 for preparation of28a. The yield for 33b is 66%, and the NMR result of 33b is as follows:

¹HNMR (300 MHz, CDCl₃): δ=16.62 (d, J_(PH)=6.8 Hz, 1H, Ru═CH), 8.53 (dd,J=2.6, 9.0 Hz, 1H), 7.55-7.39 (m, 16H), 7.27 (d, J=9.0 Hz, 1H),5.52-5.47 (m, 1H, OCHMe₂), 1.91 (d, J=6.0 Hz, 6H).

Example 41 Synthesis of Ru Complex with PCy₃ and2-Isopropoxy-5-nitrobenzylidene Ligand (34b)

The synthetic procedure is the same as in Example 37 for preparation of34a. The yield for 34b is 71%, and the NMR result of 34b is as follows:

¹HNMR (300 MHz, CDCl₃): δ=17.38 (d, J_(PH)=4.7 Hz, 1H, Ru═CH), 8.53 (dd,J=2.6, 8 Hz, 1H), 7.49 (m, 1H), 7.27 (d, J=8.0 Hz, 1H), 5.37 (m, 1H,OCHMe₂), 2.35-1.26 (m, 39H).

Example 42 Synthesis of Ru Complex with H₂IMes and2-Isopropoxy-5-nitrobenzylidene Ligand (10e)

The synthetic procedure is the same as in Example 38 for preparation ofcomplex 7k. The yield for 10e is 61%, and the NMR result of 10e is asfollows:

¹HNMR (300 MHz, CDCl₃): δ=16.47 (s, 1H, Ru═CH), 8.43 (dd, J=2.5, 9.2 Hz,1H), 7.82 (d, J=2.5 Hz, 1H), 7.10 (s, 4H), 6.89 (d, J=9.2 Hz, 1H),5.01-4.95 (m, 1H, OCHMe₂), 4.22 (s, 4H), 2.46 (s, 12H), 2.44 (s, 6H),1.30 (d, J=6.2 Hz, 6H).

Example 43 Synthesis of Ru Complex with PCy₃ and4-(4-Isopropoxy-3-vinyl-benzenesulfonyl)-morpholine Ligand (35a)

The synthetic procedure is the same as in Example 37 for preparation of34a. The yield for 35a is 68%, and the NMR result of 35a is as follows:

¹HNMR (300 MHz, CDCl₃): δ=17.38 (d, 1H, J=4.39 Hz), 8.12 (d, 1H, J=2.20Hz), 8.01 (dd, 1H, J=2.20, 8.79 Hz), 7.22 (d, 1H, J=8.79 Hz), 5.35 (m,1H), 3.79 (t, 4H, J=4.77 Hz), 3.11 (t, 4H, J=4.76 Hz), 2.35-1.29 (m,39H).

Example 44 Synthesis of Ru Complex with PCy₃ and4-(4-sec-Butoxy-3-vinyl-benzenesulfonyl)-morpholine Ligand (35b)

The synthetic procedure is the same as in Example 37 for preparation of34a. The yield for 35b is 57%, and the NMR results of 35b are asfollows:

¹HNMR (300 MHz, CDCl₃): δ=17.38 (d, J=4.4 Hz, 1H, Ru═CH), 8.11 (d, J=1.8Hz, 1H), 8.00 (dd, J=1.8, 8.7 Hz, 1H), 7.17 (d, J=8.7 Hz, 1H), 5.06-5.01(m, 1H, OCH), 3.78 (t, J=4.7 Hz, 4H), 3.11 (t, J=4.7 Hz, 4H), 2.44-1.03(m, 41H, PCy₃, O-^(i)Bu)). ³¹P-NMR (121 MHz, CDCl₃): δ=56.039 (s, PCy₃).

Example 45 RCM, Selecting the Ru Complexes of Examples 3-44 as Catalyst

General Procedure for RCM Catalyzed by Ru Complex in DCM: Olefinsubstrate (11, 13, 20, 22, 34, 36, or 38, 50 mg/each, respectively) wasdissolved in 1.0 mL of freshly distilled DCM in a 15 mL two-neckround-bottom flask under Ar at 20-25° C., then Ru catalyst (2 mol % of7a-7k or 9a-9j, respectively) was added into the DCM solution. Thekinetic data for conversion of RCM reactions in Equations 1-7 weredetermined by HPLC at 10 min., 30 min. 1.5 hr, 3.0 hr, until completedovernight. The RCM product (12, 14, 21, 23, 35, 37, or 39, respectively)was determined and the conversion results of RCM reactions were listedin Tables 1-4, respectively.

12: ¹HNMR (400 MHz, CDCl₃): δ=7.78 (d, 2H, J=8.21 Hz), 7.31 (m, 7H),6.01 (m, 1H), 4.47 (m, 2H), 4.30 (m, 2H), 2.41 (s, 3H). (M+H⁺): m/zcalculated: 300.1. found: 300.2.

14: ¹HNMR (400 MHz, CDCl₃): δ=7.15 (d, 1H, J=2.74 Hz), 6.84 (d, 1H,J=2.34 Hz), 6.34 (dt, 1H, J=1.95, 9.78 Hz), 5.86 (d, 1H, J=9.78 Hz),4.95 (m, 2H). (M+H⁺): m/z calculated: 200.99. found: 201.1.

23: ¹HNMR (400 MHz, CDCl₃): δ=7.70 (d, 2H, J=8.19 Hz), 7.31 (d, 1H,J=8.61 Hz), 5.21 (d, 1H, J=1.17 Hz), 4.06 (m, 2H), 3.96 (s, 2H), 2.42(s, 3H), 1.70 (s, 3H). (M+H⁺): m/z calculated: 238.1. found: 238.2.

37: ¹HNMR (300 MHz, CDCl₃): δ=7.72 (d, J=8.2 Hz, 1H), 7.32 (d, J=8.0 Hz,1H), 5.66 (d, J=4.4 Hz, 1H), 4.11 (d, J=4.4 Hz, 1H), 2.42 (s, 3H). m/zcalculated: 222.1. found: 222.2.

Example 46 CM, Selecting the Ru Complexes of 9a and 9d as Catalyst

General Procedure for Cross Metathesis (CM) Catalyzed by Ru Complex inDCM: Olefin substrate (24, 50 mg) was dissolved in 1.0 mL of freshlydistilled DCM in a 15 mL two-neck round-bottom flask under Ar at 20-25°C., then Ru catalyst (2 mol % of 19a or 19b, respectively) was addedinto the DCM solution. The kinetic data for conversion of RCM reactionwas determined by HPLC at 10 min., 30 min. 1.5 hr, 3.0 hr, untilcompleted overnight. The RCM product 25 was determined in high yield andthe conversion results of RCM reactions was listed in Equation 5.

25: ¹HNMR (400 MHz, CDCl₃): δ=7.54 (d, 4H, J=7.24 Hz), 7.39 (t, 4H,J=7.43 Hz), 7.28 (t, 2H, J=7.43 Hz), 7.14 (s, 2H). (M+H⁺): m/zcalculated: 181.1. found: 181.2.

1. A ruthenium catalyst having the following structure I:

wherein: X¹ and X² are the same or different and each selected fromelectron-withdrawing anionic ligands, wherein X¹ and X² may be linked toeach other via carbon-carbon and/or carbon-heteroatom bonds; Y is aneutral two-electron donor selected from oxygen, sulfur, nitrogen orphosphorus; R is H, halogen atom, alkyl, alkoxy, aryl, aryloxy,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl,heteroaryl, carboxyl (RCO₂—), cyano, nitro, amido, amino, aminosulfonyl,N-heteroarylsulfonyl, alkylsulfonyl, arylsulfonyl, alkylsulfinyl,arylsulfinyl, alkylthio, arylthio, or sulfonamido group; R¹ and R² areeach H, Br, I, alkyl, alkoxy, aryl, aryloxy, alkylcarbonyl,arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, carboxyl, amido, amino,heteroaryl, alkylthio, arylthio, or sulfonamido group; R³ is an alkyl,aryl, heteroaryl, alkylcarbonyl, arylcarbonyl, thiocarbonyl, oraminocarbonyl group; EWG is chloro or CO₂Me; and L is an electrondonating ligand, which may be linked to X¹ via carbon-carbon and/orcarbon-heteroatom bonds.
 2. The ruthenium catalyst according to claim 1,wherein X¹ and X² are each selected from an anionic ligand of halides,carboxylates, or aryloxides.
 3. The ruthenium catalyst according toclaim 2, wherein X¹ and X² each is a halogen.
 4. The ruthenium catalystaccording to claim 3, wherein X¹ and X² each is chloride (Cl).
 5. Theruthenium catalyst according to claim 1, wherein Y is oxygen (O).
 6. Theruthenium catalyst according to claim 1, wherein R is H, halogen atom,alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl, amido,alkylsulfonyl, arylsulfonyl, alkylthio, arylthio, or sulfonamido group.7. The ruthenium catalyst according to claim 6, wherein R is H, Cl, F,or C₁₋₈ alkoxycarbonyl group.
 8. The ruthenium catalyst according toclaim 1, wherein R¹ and R² each is H, alkoxy, aryl, aryloxy,alkoxycarbonyl, amido, alkylthio, arylthio, or sulfonamido group.
 9. Theruthenium catalyst according to claim 8, wherein R¹ is H or alkoxygroup, and R² is H.
 10. The ruthenium catalyst according to claim 1,wherein R³ is an alkyl, aryl, heteroaryl, alkylcarbonyl, or arylcarbonylgroup.
 11. The ruthenium catalyst according to claim 10, wherein R³ isisopropyl, sec-butyl, methoxyethyl.
 12. The ruthenium catalyst accordingto claim 1, wherein L is an electron donating ligand selected fromphosphine, amino, aryloxides, carboxylates; or heterocyclic carbenegroup, which may be linked to X¹ via carbon-carbon and/orcarbon-heteroatom bonds.
 13. The ruthenium catalyst according to claim12, wherein L is heterocyclic carbene ligand or phosphine P(R⁸)₂(R⁹)having the following structure IIa, IIb, IIc, or IId:

wherein: R⁴ and R⁵ each is C₆₋₁₂ aryl; and R⁶ and R⁷ each is H, halogen,alkyl, alkoxy, aryl, aryloxy, alkylcarbonyl, arylcarbonyl,alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl, cyano, nitro,amido, amino, alkylsulfonyl, arylsulfonyl, alkylsulfinyl, arylsulfinyl,alkylthio, arylthio, or sulfonamido group; and R⁸ and R⁹ each is C₁₋₈alkyl or C₆₋₁₂ aryl.
 14. The ruthenium catalyst according to claim 13,wherein L is IIa or IId, R⁴ and R⁵ each is 2,4,6-trimethylphenyl(mesityl), R⁶ and R⁷ each is H, and R⁸ and R⁹ each is cyclohexyl (Cy).15. A method of making a polymer, comprising reacting one or moremonomers in the presence of the catalyst of claim
 1. 16. A method ofcarrying out a metathesis reaction, comprising reacting a substrate toconduct an intramolecular RCM reaction, an intermolecular CM reaction oran intermolecular ROMP reaction in the presence of the catalyst ofclaim
 1. 17. The ruthenium catalyst according to claim 1, wherein EWG ischloro.
 18. The ruthenium catalyst according to claim 13, wherein EWG isCO₂Me.